Lead-covering of electric cables and the like by extrusion



VF? Z 3 4 f i Feb. 4, 1930. JUDGE 1,745,371

LEAD COVERING OF ELECTRIC CABLES AND THE LIKE BY EXTRUSION Filed April 20, 1.929

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Patented Feb. 4, 1930 UNITED STATES PATENT OFFICE ERNEST EDWARD JUDGE, F GRAVESEND, ENGLAND, ASSIGNOR TO W. T. HENLEYS TELEGRAPH WORKS COMPANY LIMITED, 01 LONDON, ENGLAND, A. BRITISH COM- PANY LEAD-COVERING OF ELECTRIC CABLES AND THE LIKE BY EXTRUSION Application filed April 20, 1929, Serial No. 356,634, and in Great Britain June 2, 1928.

paratus as used heretofore for this purpose.

More particularly the invention relates to the nose or point of the die which, it has been found, is liable to become displaced longitudinally by the pressure on the lead to be extruded, and the chief aim of the present invention is to'prevent, or to reduce to a negligible minimum, such longitudinal move- 7 ment.

If the nose or point be mounted directly on the end of a tubular point carrier the necessarily robust construction, especially of said carrier, is such that an undesirable area is presented to the pressure of the lead to be extruded with the result that said nose or point is. liable to be forced back slightly by said pressure. In some cases the nose or point has been mounted on an auxiliary tubular carrier fitted within the main carrier and adapted to be screwed up against a conical seating at the forward end of the latter, but this construction presents the disadvantage that any changing of the nose or point and its auxiliary carrier, necessitated, for example, by a change of size in the cable to be leadcovered, cannot be eflected from the forward end where the corresponding change is made in the die through which the extrusion is to take place, whilst any forcing back of the main carrier is communicated to the auxiliary carrier and to the point.

In accordance with the present invention the nose or point of such extrusion apparatus is slidably mounted within a ring mounted on the main carrier, said nose or point being adapted to abut at its rear end against the forward end of a tube adapted to be slidden into the main carrier from the forward end thereof, and to abut against said main carrier at, its rear end, so as to constitute a distance piece for said nose or point, the

jority of the end area presented to the pressure of the lead is that of the main carrier and ring which, if and when forced back, can slide relatively to the nose or point and its tubular distance piece.

The invention is illustrated by the accompanying drawings, wherein Figures 1, 2 and 3 are central longitudinal sections showing modifications in the nose or point, the rings and the distance pieces to suit the external diameter of the lead to be extruded.

In each case the nose or point a is slidably mountedin a ring I) which is itself mounted at the forward end of the main tubular carrier 0 so as to abut against a shoulder 41 formed in said carrier 0, whilst the nose or point a is adapted to abut against the forward end of a tubular distance piece 6 slidden into the tubular carrier 0 from the forward end thereof and adapted to abut against a shoulder 7 formed in said carrier 0 near its rear end. As shown in Figure 1 the ring I) may be formed internally with holes or recesses such as g for engagement by a key to facilitate withdrawal of the ring I) from the main carrier 0.

As shown in Figures 2 and 3 the thicknesses of the ring I) and of the distance piece 6 is increased as the size of the nose or point a is decreased, the forward end of said distance piece being shouldered as at h and spaced from the adjacent end of the ring I).

In use the pressure of the lead to be extruded acting against the combined end area of the main carrier 0 and ring I) may cause the forward parts of those members to be forced back slightly in which event they will slide relatively to the nose or oint a and the tubular distance piece e, whi st the pressure acting against the relatively smallerend area of the nose or point a will be resisted by the tubular distance piece 6 which abuts against the shoulder f at the rear end of the main carrier 0 which is not liable to be moved, moreover the pressure acting against the nose or point a will be less than that acting against the ring b and carrier 0 because the former is immediately opposite the open end of the die and also because a reduced area is presented to the pressure of the lead.

I claim z- 1. A nose or point for use in a paratus for the lead-covering of electric ca les and the like b extrusion, wherein the nose or point is sli ably mounted within a ring which is itself mounted at the forward end of a main carrier so as to abut against a shoulder therein, whilst said nose or point is adapted to abut at its rear end against the forward end of a tube Within said main carrier and prefera-bly adapted to be slidden thereinto from the front end thereof, said tube being adapted to abut against said main-carrier at its rear end so as to constitute a distance piece for said nose or polnt, substantially as set forth.

2. Apparatus for the lead-covering of electric cables and the like by extrusion comprising a nose or point slidably mounted within a ring, a tubular main carrier, said ring being mounted at the forward end of said main carrier, which is provided within one end with a shoulder against which 'said ring abuts. a tube slidably mounted within said main carrier, the rear end of said nose or point abutting against said tube and the rear end of said tube abutting against a shoulder within and at the rear end of said main carrier and constituting a'distance piece for said nose or point, the end area of said main carrier and ring presented to the pressure of the lead, being greater than that of said nose or point.

ERNEST EDWARD JUDGE. 

